共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
4.
5.
J. M. Garcia-Ruiz J. L. Martin-Vivaldi Caballero 《Crystal Research and Technology》1982,17(10):1209-1215
Single and transparent crystals of potassium sulphate up to 30 × 3 × 3 mm in size have been grown by silica gel technique, using various methods (two-layers three-layers and hybrid gel technique) which are described. The effects of the three differents alcohols (used as top solutions) upon the quality and nucleation of crystals are also reported. The “growth and equilibrium” morphologies and microstructures of the habit faces are discussed. 相似文献
6.
7.
8.
9.
10.
P. B. V. Prasad 《Crystal Research and Technology》1992,27(4):457-461
Crystallization of thin crystals of urea by hot wall condensation technique is described. Powder X-Ray diffraction (XRD) reveals the some decomposition of ura takes place during evaporation. 相似文献
11.
Information obtained owing to aquaintance with the course of the angular dependence of photoelectron intensity excited by the X-ray standing waves allows to determine, more explicitly, the state of crystal surface layer deformation. The aim of this work is to present a new measuring device constructed at the Institute of Physics of the Polish Academy of Sciences, especially the X-ray microcamera being simultaneously the proportional flowing counter used for measuring of photoelectron current emitted from the examined crystal. The angular dependence of the photoelectron current can be measured in coincidence with the angular running of rocking-curves. It is possible due to a computer program controlling the X-ray doble-crystal spectrometer, the microcamera and the electronic system for registration of the intensity of the diffracted beam as well the flowing counter. The scheme of the X-ray double-crystal spectrometer, the microcamera, and the electronic measuring system operation is given. There are also given the results of the introductory measurements carried out for the Si(111) implanted with the Au ions. The calculation of rocking-curve for non-disturbed crystal in the case of asymmetrically cut monochromator crystal was made. There was also estimated the range of depth from that the photoelectrons were emitted. 相似文献
12.
GaAs crystals having dislocation densities of 1–2 103 cm−2 were grown using VGF technique. In the grown crystals SiGa is the dominant donor and CAs the dominant acceptor. Theoretical and experimental investigations have shown the possibilities to influence on the silicon and carbon content in GaAs. Based on these results, semiinsulating properties in the crystals could be achieved reproducibly. 相似文献
13.
本文报道了坩埚下降法生长大尺寸白宝石单晶.我们使用大尺寸异型钼坩埚,高纯氧化铝原料,在中性气氛下,结晶区温度梯度为25~30℃/cm,生长速度为0.8~1.8mm/h,生长方向选C面[0001]取向,成功生长出直径80mm,高度90mm的完整透明的白宝石单晶,在300~5500nm范围内,其光学透过率均在80;以上.实验中采用高性能保温材料使生长过程所需加热功率由20kW下降到15kW,能耗降低达25;;采用双回路加热系统,提高温场稳定性,缩短晶体生长周期.晶体的主要缺陷为顶部(生长后期)出现有5~10mm淡黄色色带(经在氧化性气氛中退火后已消除)和底部有细丝状条纹. 相似文献
14.
15.
16.
17.
18.
In this paper the principle of GaP synthesis by the SSD technique is described followed by a discussion of the results obtained in studying the transfer of an impurity such as the highly volatile zinc from the phosphorus source or gallium melt into GaP crystals. The radionuclide Zn65 was used as a tracer to determine the concentrations of zinc in the phases involved in the process of synthesis. The results of these studies are compared with calculated values. 相似文献
19.
K. Watanabe 《Crystal Research and Technology》1999,34(1):47-52
Single crystals of neodymium pentaphosphate, NdP5O14, were grown by the flux seeded technique. The optimum growth conditions are scribed for obtaining a large crystal having well-developed faces with good quality. 相似文献
20.
V. A. Borodin E. A. Brener T. A. Steriopolo V. A. Tatarchenko L. I. Chernishova 《Crystal Research and Technology》1982,17(10):1199-1207
The authors analyze the process of corundum tube growth by modified Verneuil's method from the viewpoint of its stability. The article shows that the process is stable in the case of thin-walled tubes and becomes unstable when the tube wall thickness exceeds a certain critical value which is known to be below the capillary constant. The critical thickness of the tube wall grows with a decrease of the heat flux density differential from the burner along the furnace muffle and with an increase of the tube's outer radius. As a result of a process of crystal growth under preset conditions constant cross-section single crystaal corundum tubes have been obtained. 相似文献